What type of sign warns drivers of existing or possible roadway hazards?

The diamond sign is used to warn drivers of existing or potential roadway hazards. This type of sign typically features a yellow background with black symbols or text and is designed to alert drivers to cautionary situations such as sharp curves, pedestrian crossings, or construction zones. The diamond shape is universally recognized as a warning symbol, making it immediately identifiable to motorists. It helps ensure drivers are aware of hazards ahead, allowing them to adjust their speed or driving behavior accordingly for safety.

The other sign types mentioned serve different purposes: vertical rectangle signs often provide regulatory information, octagon signs are exclusively used for stop signs, and round signs are typically used to indicate railroads. Each sign shape conveys a specific message, and recognizing the function of each can significantly improve road safety.